Orthodox vs Catholic Easter Observance

According to Danial Paul Davis....

Both are commemorating the same thing: the resurrection of Yeshua ha Meschiach, Jesus the Messiah, from death.

The only difference is the date: the Roman Catholic method is (take a deep breath) the first Sunday after the first full moon after the vernal equinox. "First Sunday" is a margin of 7 days; "full moon" is a margin of 29 days; "vernal equinox" is a margin of 3 days (20th, 21st, or 22nd.) Easter could be within a 39 day span, basically, as early as March 22 (equinox on 20th, full moon on Saturday the 21st.) Or the full moon could have been the 21st, the Equinox would be the 22nd, the full moon 28 days later, April 18. "Thus the date of Easter is from March 22 through April 25, inclusive."
"The Greek Orthodox Church does not always celebrate Easter on the same day as the Catholic and Protestant countries. The reason is that the Orthodox Church uses the Julian calendar when calculating Easter." <http://www.webexhibits.org/calendars/calendar-christian-easter.html#anchor-orthodox>. "This is case even in the churches that otherwise use the Gregorian calendar. When the Greek Orthodox Church in 1923 decided to change to the Gregorian calendar (or rather: a Revised Julian Calendar), they chose to use the astronomical full moon as the basis for calculating Easter, rather than the "official" full moon described in the previous sections. And they chose the meridian of Jerusalem to serve as definition of when a Sunday starts. However, except for some sporadic use in the 1920s, this system was never adopted in practice."
Weird, huh

Source:
http://www.smart.net/~mmontes/ec-cal.html